Control circuit for a variable vane oil pump

ABSTRACT

A control circuit for a variable vane oil pump of an automatic transmission vehicle may include the variable vane oil pump supplying a working fluid for controlling the automatic transmission, a regulator valve mounted at a hydraulic line fluid-connected to the variable vane oil pump, and a torque converter control valve fluid-connected to the regulator valve for controlling the working fluid supplied from the regulator valve to have a pressure required in a torque converter, wherein the variable vane oil pump may be controlled by an amount of the working fluid discharged from the torque converter control valve.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. -2011-0132261 filed in the Korean Intellectual Property Office on Dec. 9, 2011, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention includes a control circuit for a variable vane oil pump. More particularly, the present invention relates to a control circuit for a variable vane oil pump in which a cam ring of the variable vane oil pump may be optimally controlled.

2. Description of Related Art

In general, a transmission control unit (TCU) for an automatic transmission controls a friction element (operation element) such as a clutch and a brake by controlling a plurality of solenoid valves.

A discharging flow of a fixed oil pump is generally small at a low speed and large at a high speed.

However, a discharging performance of the oil pump required for lubricating, cooling, and operating friction element is determined in hot idle condition having a low speed and a high temperature, as a result a discharging flow of the oil pump in a high speed becomes larger than a required flow, such that a loss occurs and a fuel efficiency decreases.

The conventional fixed oil pump must have changed capacity by adjusting the width of a rotor or changing size of the rotor so as to control discharging performance. But the fuel efficiency also decreases in this case since unnecessary flow occurs in a high speed of the oil pump either.

Meanwhile, a variable oil pump may be a key component for improving fuel efficiency and overcoming limitation of the fixed oil pump. The variable oil pump to be applied to a transmission is generally a vane type which is mainly being developed by component developing companies in Europe and North America.

The variable vane oil pump continuously changes outflow of oil so as to optimally control pressure and flux of oil which is used for lubricating and driving operational elements of the transmission.

FIG. 1 is exploded perspective view of a variable vane oil pump according to the conventional art. The conventional variable vane oil pump, as shown in FIG. 1, may include a housing 1 in which a port is formed, a rotor 3 in which a plurality of vanes 2 are formed at the exterior circumference, a cam ring 4 mounted at the circumference of the rotor 3, a spring 5 supplying the cam ring 4 elastically, a pivot pin 6 for rotatably fixing the cam ring to the housing, and a cover 7.

The variable vane oil pump changes outflow of oil by changing the volume of the pump. The volume of the pump can be changed by changing an eccentric in the pump by providing control pressure to the cam ring.

In the conventional art, the control pressure is generally produced by using a solenoid, using an exhaust flow of a regulator valve or feedback of outflow of the pump.

However, if the control pressure is generated by using the solenoid, the cost increases and the layout becomes difficult by adding the solenoid. Further, if the control pressure is generated by using the exhaust flow of the regulator valve or using feedback of the outflow of the pump, as shown in FIG. 2, control responsiveness and suction performance of the pump become worse.

The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a control circuit for a variable vane oil pump having advantages of improving responsiveness of variable control and enlarging flow for controlling the variable vane oil pump.

In an aspect of the present invention, a control circuit for a variable vane oil pump of an automatic transmission vehicle may include the variable vane oil pump supplying a working fluid for controlling the automatic transmission, a regulator valve mounted at a hydraulic line fluid-connected to the variable vane oil pump, and a torque converter control valve fluid-connected to the regulator valve for controlling the working fluid supplied from the regulator valve to may have a pressure required in a torque converter, wherein the variable vane oil pump is controlled by an amount of the working fluid discharged from the torque converter control valve.

An exhaust line of the torque converter control valve is fluid-connected to a control line of the variable vane oil pump such that the variable vane oil pump is controlled by the amount of the working fluid discharged from the torque converter control valve.

The working fluid discharged from an outflow line fluid-connected to the regulator valve flows to an inflow line connected to the variable vane oil pump.

The working fluid of the torque converter flows into an oil filter and an oil pan through a first pipe line branched from the exhaust line, and enters the variable vane oil pump through a second pipe line after passing through the oil filter and the oil pan.

The second pipe line is fluid-connected to the inflow line.

An orifice is formed at each of the control line and the first pipe line.

In another aspect of the present invention, the exhaust line of the torque converter control valve and the outflow line of the regulator valve are fluid-connected with each other to a third pipe line, and the third pipe line is connected to the control line of the variable vane oil pump.

The working fluid of the torque converter flows into the oil filter and the oil pan through a fourth pipe line branched from the third pipe line, and enters the variable vane oil pump through a fifth pipe line after passing through the oil filter and the oil pan.

The fifth pipe line is fluid-connected to the inflow line.

An orifice is formed at each of the fourth pipe line and the control line.

The control circuit for a variable vane oil pump according to an exemplary embodiment of the present invention may improve responsiveness of variable control, optimally control a flow of transmission after producing turbocharger (T/C) pressure, and prevent cavitation.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a variable vane oil pump.

FIG. 2 is a schematic diagram of a variable vane oil pump according to the conventional art.

FIG. 3 is a schematic diagram of a control circuit for a variable vane oil pump according to an exemplary embodiment of the present invention.

FIG. 4 is a schematic diagram of a control circuit for a variable vane oil pump according to another exemplary embodiment of the present invention.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

An exemplary embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 3 is a schematic diagram of a control circuit for a variable vane oil pump according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the control circuit for a variable vane oil pump according to an exemplary embodiment of the present invention may include a variable vane oil pump 20 supplying a working fluid for controlling the automatic transmission, a regulator valve 30 mounted at a hydraulic line 21 of the variable vane oil pump 20, and a torque converter control valve 40 for controlling the working fluid supplied from the regulator valve 30 to have a pressure required by a torque converter, wherein the variable vane oil pump 20 is controlled by the amount of working fluid discharged from the torque converter control valve 40.

The variable vane oil pump 20 is connected to the hydraulic line 21 for exhausting working fluid, a control line 22 for controlling the variable vane oil pump 20, and an inflow line 23 suctioning the working fluid, respectively.

The variable vane oil pump 20 may include a housing in which a port is formed, a rotor in which a plurality of vanes are formed at the exterior circumference, a cam ring mounted at the circumference of the rotor, a spring supplying the cam ring with elasticity, a pivot pin for rotatably fixing the cam ring to the housing, and a cover.

A working fluid exhausted from the variable vane oil pump 20 is supplied to the regulator valve 30 through the hydraulic line 21.

At the regulator valve 30 according to an exemplary embodiment of the present invention, as shown in FIG. 3, an outflow line 31 is connected to the inflow line 23 of the variable vane oil pump 20.

A part of the working fluid exhausted from the variable vane oil pump 20 flows into the variable vane oil pump 20 again by passing through the outflow line 31 and the inflow line 23. As a result, a suctioning negative pressure of the variable vane oil pump 20 increases, and cavitation of the variable vane oil pump 20 is prevented.

Meanwhile, a control pressure controlled by the regulator valve 30 flows into the torque converter control valve 40 by passing through a supply line 32 of the regulator valve 30.

The torque converter control valve 40 controls a pressure to a required pressure in a torque converter of an automatic transmission. The torque converter control valve 40 controls the torque converter using a control pressure produced by inflow working fluid exhausted from the regulator valve 30.

In the variable vane oil pump control circuit according to an exemplary embodiment of the present invention, as shown in FIG. 3, an exhaust (Ex) line 41 of the torque converter control valve 40 is directly connected to the control line 22 of the variable vane oil pump 20.

The variable vane oil pump 20 is controlled by the amount of working fluid discharged from the exhaust (EX) line 41 of the torque converter control valve so that the variable vane oil pump 20 can be optimally controlled after producing torque converter (T/C) pressure and line pressure inside the automatic transmission.

In some exemplary embodiments, as shown in FIG. 3, the exhaust line 41 of the torque converter control valve 40 may be divided into two lines of which one line is connected to the control line 22 of the variable vane oil pump 20 and the other line is connected to a first pipe line 51 communicating with an oil filter 50 or oil pan 60.

The oil filter 50 filters out impurities of the working fluid so as to reuse the working fluid.

An exhaust fluid of the first pipe line 51 and oil in the transmission are gathered in the oil pan 60, and the oil pan 60 supplies the exhaust fluid of the first pipe line 51 and the oil in the transmission to the variable vane oil pump 20 through a second pipe line 52.

A detailed explanation of the structure and operation of the oil filter 50 and oil pan 60 will be omitted since these are well known to a person of ordinary skill in the art.

As shown in FIG. 3, according to an exemplary embodiment of the present invention, the amount of working fluid flowing into the variable vane oil pump 20 can be increased. Because the outflow line 31 of the regulator valve 30 and the second pipe line 52 are connected with other so that the exhaust fluid of the regulator valve is added to the exhaust fluid of the oil pan 60, cavitation of the pump can be effectively prevented by the increasing amount of working fluid.

Further, an orifice 70 may be formed at each of the exhaust line 41 of the torque converter control valve 40 and the first pipe line 51. As a result, rapid pressure deterioration in the control line 22 can be prevented since the orifice controls the flow of the exhaust line 41 and the control line 22. The orifice 70 is formed at each of the exhaust line 41 and the first pipe line 51 having a smaller radius than the exhaust line 41 and the first pipe line 51 so as to play a role of an aperture, such that the orifice 70 can control exhaust flow and pressure.

The control circuit for a variable vane oil pump according to an exemplary embodiment of the present invention may improve responsiveness of variable control by controlling the variable vane oil pump 20 using the exhaust flow of the torque converter control valve 40, and prevent cavitation by recirculating the exhaust flow of the regulator valve 30 to the variable vane oil pump 20.

FIG. 4 is a schematic diagram of a control circuit for variable vane oil pump according to another exemplary embodiment of the present invention.

As shown in FIG. 4, a control circuit for variable vane oil pump according to another exemplary embodiment of the present invention may include: a variable vane oil pump 20 supplying a working fluid for controlling the automatic transmission, a regulator valve 30 mounted at a hydraulic line 21 of the variable vane oil pump 20, and a torque converter control valve 40 for controlling the working fluid supplied from the regulator valve 30 to have a pressure required in a torque converter, wherein an exhaust (Ex) line 41 of the torque converter control valve 40 and an outflow line 31 of the regulator valve 30 are connected with each other through a third pipe line 53, and the third pipe line 53 is connected to the control line 22 of the variable vane oil pump 30. As a result, the variable vane oil pump 20 is controlled by the amount of working fluid discharged from the torque converter control valve 40 and the regulator valve 30.

As shown in FIG. 4, a working fluid exhausted from the variable vane oil pump 20 is supplied to the regulator valve 30 through the hydraulic line 21, the outflow line 31 of the regulator valve 30 is connected to the exhaust (Ex) line 41 of the torque converter control valve 40, and as a result, the third pipe line 53 is formed.

The third pipe line 53 is connected to the inflow line 23 of the variable vane oil pump 20.

As a result, variable control responsiveness can be improved since the amount of fluid flowing through the outflow line 31 of the regulator valve 30 is added to the amount of fluid flowing through the exhaust line of the torque converter control valve 40 in the third pipe line 53 so that the amount of fluid that flows into the variable vane oil pump 20 through the third pipe line 53 is increased.

In some exemplary embodiments, as shown in FIG. 4, the third pipe line may be divided into two lines in which one line is connected to the control line 22 of the variable vane oil pump 20, and the other line is connected to a fourth pipe line 54 which is communicating with the oil filter 50 or oil pan 60.

An exhaust fluid of the fourth pipe line 54 and oil in the transmission are gathered in the oil pan 60, and the oil pan 60 supplies the exhaust fluid of the fourth pipe line 54 and the oil in the transmission to the variable vane oil pump 20 through a fifth pipe line 55.

Further, an orifice 70 may be formed at the control line 22 and the fourth pipe line 54 for controlling flow. The orifice 70 is formed at each of the control line 22 and the fourth pipe line 54 having a smaller radius than the control line 22 and the fourth pipe line 54 so as to play a role as an aperture, such that the orifice 70 can control exhaust flow and pressure.

As shown in FIG. 4, the control circuit for the variable vane oil pump according to another exemplary embodiment of the present invention may improve control responsiveness by controlling the variable vane oil pump 20 using the exhaust flow of the torque converter control valve 40 and the exhaust flow of the regulator valve 30.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

What is claimed is:
 1. A control circuit for a variable vane oil pump of an automatic transmission vehicle, comprising: the variable vane oil pump supplying a working fluid for controlling the automatic transmission; a regulator valve mounted at a hydraulic line fluid-connected to the variable vane oil pump; and a torque converter control valve fluid-connected to the regulator valve for controlling the working fluid supplied from the regulator valve to have a pressure required in a torque converter, wherein the variable vane oil pump is controlled by an amount of the working fluid discharged from the torque converter control valve.
 2. The control circuit of claim 1, wherein an exhaust line of the torque converter control valve is fluid-connected to a control line of the variable vane oil pump such that the variable vane oil pump is controlled by the amount of the working fluid discharged from the torque converter control valve.
 3. The control circuit of claim 2, wherein the working fluid discharged from an outflow line fluid-connected to the regulator valve flows to an inflow line connected to the variable vane oil pump.
 4. The control circuit of claim 3, wherein the working fluid of the torque converter flows into an oil filter and an oil pan through a first pipe line branched from the exhaust line, and enters the variable vane oil pump through a second pipe line after passing through the oil filter and the oil pan.
 5. The control circuit of claim 4, wherein the second pipe line is fluid-connected to the inflow line.
 6. The control circuit of claim 4, wherein an orifice is formed at each of the control line and the first pipe line.
 7. The control circuit of claim 3, wherein the exhaust line of the torque converter control valve and the outflow line of the regulator valve are fluid-connected with each other to a third pipe line, and the third pipe line is connected to the control line of the variable vane oil pump.
 8. The control circuit of claim 7, wherein the working fluid of the torque converter flows into the oil filter and the oil pan through a fourth pipe line branched from the third pipe line, and enters the variable vane oil pump through a fifth pipe line after passing through the oil filter and the oil pan.
 9. The control circuit of claim 8, wherein the fifth pipe line is fluid-connected to the inflow line.
 10. The control circuit of claim 8, wherein an orifice is formed at each of the fourth pipe line and the control line. 